• Title/Summary/Keyword: Transcriptional Activity

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Molecular Cloning, Protein Expression, and Regulatory Mechanisms of the Chitinase Gene from Spodoptera littoralis Nucleopolyhedrovirus

  • Yasser, Norhan;Salem, Reda;Alkhazindar, Maha;Abdelhamid, Ismail A.;Ghozlan, Said A.S.;Elmenofy, Wael
    • Microbiology and Biotechnology Letters
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    • v.49 no.3
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    • pp.305-315
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    • 2021
  • The cotton leafworm, Spodoptera littoralis, is a major pest in Egypt and many countries worldwide, and causes heavy economic losses. As a result, management measures to control the spread of the worm are required. S. littoralis nucleopolyhedrovirus (SpliNPV) is one of the most promising bioagents for the efficient control of insect pests. In this study, a chitinase gene (chitA) of a 1.8 kb DNA fragment was cloned and fully characterized from SpliNPV-EG1, an Egyptian isolate. A sequence of 601 amino acids was deduced when the gene was completely sequenced with a predicted molecular mass of 67 kDa for the preprotein. Transcriptional analyses using reverse transcription polymerase chain reaction (RT-PCR) revealed that chitA transcripts were detected first at 12 h post infection (hpi) and remained detectable until 168 hpi, suggesting their transcriptional regulation from a putative late promoter motif. In addition, quantitative analysis using quantitative RT-PCR showed a steady increase of 7.86-fold at 12 hpi in chitA transcription levels, which increased up to 71.4-fold at 120 hpi. An approximately 50 kDa protein fragment with chitinolytic activity was purified from ChitA-induced bacterial culture and detected by western blotting with an anti-recombinant SpliNPV chitinase antibody. Moreover, purification of the expressed ChitA recombinant protein showed in vitro growth inhibition of two different fungi species, Fusarium solani and F. oxysporum, confirming that the enzyme assembly and activity was correct. The results supported the potential role and application of the SpliNPV-ChitA protein as a synergistic agent in agricultural fungal and pest control programs.

Aqueous extract of Petasites japonicus leaves promotes osteoblast differentiation via up-regulation of Runx2 and Osterix in MC3T3-E1 cells

  • Kim, Eun Ji;Jung, Jae In;Jeon, Young Eun;Lee, Hyun Sook
    • Nutrition Research and Practice
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    • v.15 no.5
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    • pp.579-590
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    • 2021
  • BACKGROUND/OBJECTIVES: Petasites japonicus Maxim (P. japonicus) has been used as an edible and medicinal plant and contains many bioactive compounds. The purpose of this study is to investigate the effect of P. japonicus on osteogenesis. MATERIALS/METHODS: The leaves and stems of P. japonicus were separated and extracted with hot water or ethanol, respectively. The total phenolic compound and total polyphenol contents of each extract were measured, and alkaline phosphatase (ALP) activity of each extract was evaluated to determine their effect on bone metabolism. To investigate the effect on osteoblast differentiation of the aqueous extract of P. japonicus leaves (AL), which produced the highest ALP activity among the tested extracts, collagen content was measured using the Sirius Red staining method, mineralization using the Alizarin Red S staining method, and osteocalcin production through enzyme-linked immunosorbent assay analysis. Also, real-time reverse transcription polymerase chain reaction was performed to investigate the mRNA expression levels of Runt-related transcriptional factor 2 (Runx2) and Osterix. RESULTS: Among the 4 P. japonicus extracts, AL had the highest values in all of the following measures: total phenolic compounds, total polyphenols, and ALP activity, which is a major biomarker of osteoblast differentiation. The AL-treated MC3T3-E1 cells showed significant increases in induced osteoblast differentiation, collagen synthesis, mineralization, and osteocalcin production. In addition, mRNA expressions of Runx2 and Osterix, transcription factors that regulate osteoblast differentiation, were significantly increased. CONCLUSIONS: These results suggest that AL can regulate osteoblasts differentiation, at least in part through Runx2 and Osterix. Therefore, it is highly likely that P. japonicus will be useful as an alternate therapeutic for the prevention and treatment of osteoporosis.

Polymorphisms and Functional Analysis of the Intact Human Papillomavirus16 E2 Gene

  • Ekalaksananan, Tipaya;Jungpol, Watcharapol;Prasitthimay, Chuthamas;Wongjampa, Weerayut;Kongyingyoes, Bunkerd;Pientong, Chamsai
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10255-10262
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    • 2015
  • High risk human papillomavirus (HR-HPV) E2 proteins play roles in transcriptional regulation and are commonly functionally disrupted when the HPV genome integrates into host chromosomes. Some 15-40% of cancer cases, however, contain an intact E2 gene or episomal HPV. In these cases, polymorphism of the E2 gene might be involved. This study aimed to determine polymorphisms of the E2 gene in episomal HPV16 detected in high grade squamous intraepithelial lesions and squamous cell carcinomas and altered functions compared to the E2 prototype. The E2 gene was amplified and sequenced. Two expression vectors containing E2 gene polymorphisms were constructed and transfected in SiHa and C33A cells, then E6 gene as well as Il-10 and TNF-${\alpha}$ expression was determined by quantitative RT-PCR. Expression vectors and reporter vectors containing the HPV16 long control region (LCR) were co-transfected and transcriptional activity was determined. The results showed that a total of 32 nucleotides and 23 amino acids were changed in all 20 cases of study, found in the transactivation (TA) domain, hinge (H) region and DNA binding (DB) domain with 14, 5 and 13 nucleotide positions. They mostly caused amino acid change. The expressing vectors containing different E2 gene polymorphisms showed E6 mRNA suppression, TNF-${\alpha}$ mRNA suppression and IL-10 induction but no statistically significant differences when compared to the E2 prototype. Moreover, promoter activity in HPV16 LCR was not affected by E2 protein with different gene polymorphisms, in contrast to nucleotide variations in LCR that showed an effect on transcription activity. These results demonstrated that E2 gene polymorphisms of episomal HPV16 did not affect transcriptional regulation and suggested that nucleotide variation as well as epigenetic modification of the LCR might play a role in inducing malignant transformation of cells containing episomal HPV16.

Regulation of cellular functions of p53 by ubiquitination (유비퀴틴화에 의한 세포 내 p53의 기능 조절)

  • Jung, Jin-Hyuk;Lee, Joon-Young;Lee, Sun-Mi;Choe, Tae-Boo;An, Sung-Kwan
    • KSBB Journal
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    • v.24 no.3
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    • pp.217-226
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    • 2009
  • p53 undergoes various post-translational modifications, including phosphorylation, ubiquitination, sumoylation, acetylation, methylation, and poly(ADP-ribosyl)ation. Modification of p53 widely affects to various functions of p53. Acetylation and phosphorylation of p53 have been studied for regulating its transcriptional activity which is observed in various stress condition. Otherwise, ubiquitination of p53 by Mdm2 has been well-studied as a canonical ubiquitin-mediated proteasomal degradation pathway. Moreover several investigators have recently reported that ubiquitination of p53 modulates not only its proteasome-dependent degradation by poly-ubiquitination but also its localization and transcriptional activity by mono-ubiquitination which usually does not serve the proteasome dependent degradation. Here we review recent studies on the cellular functions of p53 regulated by post-translational modifications, particularly focusing on mechanisms of ubiquitination.

Inactivation of the DevS Histidine Kinase of Mycobacterium smegmatis by the Formation of the Intersubunit Disulfide Bond (Subunit 간의 disulfide 결합 형성에 의한 Mycobacterium smegmatis DevS histidine kinase의 불활성화)

  • Lee, Jin-Mok;Park, Kwang-Jin;Kim, Min-Ju;Ko, In-Jeong;Oh, Jeong-Il
    • Journal of Life Science
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    • v.20 no.6
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    • pp.853-860
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    • 2010
  • The DevSR two-component system is a major regulatory system involved in redox sensing in Mycobacterium smegmatis. The DevSR system consists of the DevS histidine kinase and its cognate DevR response regulator. When exposed to hypoxic conditions, the DevS histidine kinase is activated to phosphorylate the DevR response regulator, leading to the transcriptional activation of the DevR regulation. The ligand-binding state of the heme embedded in the N-terminal GAF domain of DevS determines the kinase activity of DevS. In this study, we demonstrated that the redox-responsive cysteine (C547) in the C-terminal kinase domain is involved in the redox-dependent control of DevS kinase activity. The formation of an intersubunit disulfide bond between the C547 residues in the presence of $O_2$ led to inactivation of DevS kinase activity. The reduction of the oxidized DevS with reductants such as $\beta$-mercaptoethanol and dithiothreitol resulted in the restoration of DevS kinase activity. It was demonstrated in vivo by complementation test that the substitution of C547 to alanine partially impaired the sensory function of DevS in M. smegmatis.

The Anti-Inflammatory and Anti-Oxidant Activity of Ethanol Extract from Red Rose Petals

  • Kim, Hyun-Kyoung
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.139-148
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    • 2020
  • Red rose petals are usually disposed but they are an abundant source of phenolics and traditionally used as food supplement and as herbal medicine. Of the Various phenolics, they are known to have anticancer, antioxidant, and anti-inflammatory properties. In this study, we investigated the anti-inflammatory effects of red rose ethanolic extracts (GRP) on lipopolysaccharide (LPS)-activated RAW 264.7 cells. The results demonstrated that pretreatment of GRP (500㎍/mL) significantly reduced NO production by suppressing iNOS protein expression in LPS-stimulated cells. Anti-inflammatory effects by red rose petals were observed in the following. Red rose petals inhibited the translocation of NF-κB from the cytosol to the nucleus via the suppression of IκB-α phosphorylation and also inhibited LPS-stimulated NF-κB transcriptional activity. These findings suggest that red rose petals exert anti-inflammatory actions and help to elucidate the mechanisms underlying the potential therapeutic values of red rose petals. Therefore, red rose petals could be regarded as a potential source of natural anti-inflammatory agents.

A Novel Histone Methyltransferase, Kodo7 Induces Histone H3-K9 Methylation and Mediates Apoptotic Cell Death

  • Kim, Sung-Mi;Seo, Sang-Beom
    • International Journal of Oral Biology
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    • v.31 no.3
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    • pp.81-86
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    • 2006
  • SET (Suppressor of variegation, Enhancer of zeste, and the Trithorax) domain-containing proteins are known to have methyltransferase activity at lysine residues of histone proteins. In this study, we identified a novel SET domain-containing protein from mouse and named Kodo7. Indeed, Kodo7 has methyltransferase activity at K9 residue of the H3 protein as demonstrated by a histone methyl-transferse activity assay using GST-tagged Kodo7. Confocal microscopy showed that Kodo7 is co-localized with histones in the nucleus. Interestingly, ectopic expression of Kodo7 by transient transfection induced cell death and treatment of the transfectants with a caspase-3 inhibitor, Ac-DEVD-AFC decreased Kodo7-induced apoptosis. These results suggest that Kodo7 induces apoptotic cell death through increased methylation of histones leading to transcriptional repression.

Inhibition of Overexpressed CDC-25.1 Phosphatase Activity by Flavone in Caenorhabditis elegans

  • Kim, Koo-Seul;Kawasaki, Ichiro;Chong, Youhoon;Shim, Yhong-Hee
    • Molecules and Cells
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    • v.27 no.3
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    • pp.345-350
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    • 2009
  • We previously reported that flavone induces embryonic lethality in Caenorhabditis elegans, which appeared to be the result of cell cycle arrest during early embryogenesis. To test this possibility, here we examined whether flavone inhibits the activity of a key cell cycle regulator, CDC-25.1 in C. elegans. A gain-of-function cdc-25.1 mutant, rr31, which exhibits extra cell divisions in intestinal cells, was used to test the inhibitory effects of flavone on CDC-25 activity. Flavone inhibited the extra cell divisions of intestinal cells in rr31, and modifications of flavone reduced the inhibitory effects. The inhibitory effects of flavone on CDC-25.1 were partly, if not completely, due to transcriptional repression.

Acetylshikonin Inhibits Human Pancreatic PANC-1 Cancer Cell Proliferation by Suppressing the NF-κB Activity

  • Cho, Seok-Cheol;Choi, Bu Young
    • Biomolecules & Therapeutics
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    • v.23 no.5
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    • pp.428-433
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    • 2015
  • Acetylshikonin, a natural naphthoquinone derivative compound, has been used for treatment of inflammation and cancer. In the present study, we have investigated whether acetylshikonin could regulate the NF-${\kappa}B$ signaling pathway, thereby leading to suppression of tumorigenesis. We observed that acetylshikonin significantly reduced proliferation of several cancer cell lines, including human pancreatic PANC-1 cancer cells. In addition, acetylshikonin inhibited phorbol 12-myristate 13-acetate (PMA) or tumor necrosis-${\alpha}$ (TNF-${\alpha}$)-induced NF-${\kappa}B$ reporter activity. Proteome cytokine array and real-time RT-PCR results illustrated that acetylshikonin inhibition of PMA-induced production of cytokines was mediated at the transcriptional level and it was associated with suppression of NF-${\kappa}B$ activity and matrix metalloprotenases. Finally, we observed that an exposure of acetylshikonin significantly inhibited the anchorage-independent growth of PANC-1 cells. Together, our results indicate that acetylshikonin could serve as a promising therapeutic agent for future treatment of pancreatic cancer.

Effect of Pini Folium Extract on AP-1 (c-fos/c-jun) in Cancer Cells (암세포에서 송엽의 AP-l (c-fos/c-jun)에 미치는 영향)

  • 박건구;장혜숙;이정교;최승훈
    • YAKHAK HOEJI
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    • v.43 no.1
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    • pp.42-47
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    • 1999
  • Phorbol ester, growth factors activities are mediated by unclear transcription factors, the c-Fos and c-Jun, which can regulate transcriptional activation through specific DNA sites and by forming the transcription factor AP-l, which usually mediates cell proliferation and differentiation signals. We explored effects of Pini Folium extract (API-l) on AP-l activity. Western blot analysis confirmed that API-l decreased levels of c-Fos or c-Jun protein induced by the tumor promoter Phorbol 12-myristate 13-acetate (PMA; 200 nM). Transient transfection assays with a c-fos promoter reporter construct showed that API-l decreased transcription activity by ore than 50~60%. However, treatment of API-l activity studied further. The main substances were fractionated into dichloromethane layer. Futhermore, API-l extract repressed the [$^3H$]-thymidine uptake in C6 glioma cells, indicating that this extract could be included in a new type of modulator in the mitogenesis.

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